// set it to fault later.
	if uintptr(x)%physPageSize != 0 {
		throw("user arena chunk is not aligned to the physical page size")
	}

	return x, span
}

// isUnusedUserArenaChunk indicates that the arena chunk has been set to fault
// and doesn't contain any scannable memory anymore. However, it might still be
// mSpanInUse as it sits on the quarantine list, since it needs to be swept.
//

			Mallocs, Frees uint64
		}

		// Add up current allocations in spans.
		for _, s := range mheap_.allspans {
			if s.state.get() != mSpanInUse {
				continue
			}
			if s.isUnusedUserArenaChunk() {
				continue
			}
			if sizeclass := s.spanclass.sizeclass(); sizeclass == 0 {
				slow.Mallocs++
				slow.Alloc += uint64(s.elemsize)
			} else {
				slow.Mallocs += uint64(s.allocCount)